Risk Factors for Invasive Candidiasis in Critically Ill Patients Who Underwent Emergency Gastrointestinal Surgery for Complicated Intra-Abdominal Infection

Background: Candida species account for approximately 15% of hospital-associated infections, causing fatal consequences, especially in critically ill patients. This study aimed to evaluate invasive candidiasis (IC) risk factors in critically ill patients undergoing surgery. Patients and Methods: We retrospectively reviewed the medical records of 583 patients who underwent emergency surgery for complicated intra-abdominal infections between January 2016 and December 2021. Patients were divided into two groups according to the presence or absence of IC during their hospital stay. IC was defined as culture-proven candidemia and intra-abdominal candidiasis. Results: This study included 373 patients for the final analysis, of whom 320 were discharged without IC (IC absent group) and 53 presented with IC (IC present group) during their hospital stay. The IC present group showed a higher in-hospital mortality rate (35.8 vs. 8.8%; p < 0.001), with 66.0% of the patients diagnosed within 10 days, whereas only 6.5% were diagnosed beyond 20 days after admission. Stomach (odds ratio [OR], 4.188; 95% confidence interval [CI], 1.204-14.561; p = 0.024) and duodenum (OR, 7.595; 95% CI, 1.934-29.832; p = 0.004) as infection origin, higher Acute Physiology and Chronic Health Evaluation II (APACHE II) score (OR, 1.097; 95% CI, 1.044-1.152; p < 0.001), and lower initial systolic blood pressure (OR, 0.983; 95% CI, 0.968-0.997; p = 0.018) were risk factors of IC after emergency gastrointestinal surgery. Conclusions: Patients who had stomach and duodenum as infection origin, higher APACHE II scores, and lower initial systolic blood pressure had a higher risk of developing IC during their hospital stay after emergency gastrointestinal surgery. Prophylactic antifungal agents can be carefully considered for critically ill patients with these features.

Current status of laparoscopic emergency surgery in Korea: multicenter restrospective cohort study

Purpose

Laparoscopic surgery is a choice in several emergency settings. However, there has been no nationwide study or survey that has compared the clinical use of laparoscopic emergency surgery (LES) versus open abdominal emergency surgery (OES) in Korea. Therefore, we examined the state of LES across multiple centers in Korea and further compared this data with the global state based on published reports.

Methods

Data of 2,122 patients who received abdominal emergency surgery between 2014 and 2019 in three hospitals in Korea were collected and retrospectively analyzed. Several clinical factors were investigated and analyzed.

Results

Of the patients, 1,280 (60.3%) were in the OES group and 842 (39.7%) were in the LES group. The most commonly operated organ in OES was the small bowel (25.8%), whereas that for LES was the appendix. In appendectomy and cholecystectomy, 93.7% and 88.0% were in the LES group. In small bowel surgery, gastric surgery, and large bowel surgery, 89.4%, 92.0%, and 79.1% were in the OES group. The severity-related factors of patient status demonstrated statistically significant limiting factors of selection between LES and OES.

Conclusion

Although our study has several limitations, compared to the LES data from other countries, the general LES state was similar in appendectomies, cholecystectomies, and small bowel surgeries. However, in gastric and colorectal surgeries, the LES state was different from those of other countries. This study demonstrated the LES state and limiting factors of selection between LES and OES in various operated organs. Further studies are required to analyze these differences and the various limiting factors.

Oncologic outcome of colon cancer with perforation and obstruction

Purpose

Perforation and obstruction in colorectal cancer are poor prognostic factors. We aimed to evaluate the oncological outcomes of patients with colon cancer presenting with perforation or obstruction.

Methods

A total of 260 patients underwent surgery for colon cancer between January 2015 and December 2017. Among them, 54 patients who underwent emergency surgery for perforated (n = 32) or obstructive (n = 22) colon cancer were included.

Results

The perforation (PG, n = 32) and obstruction groups (OG, n = 22) did not differ significantly in age (p = 0.486), sex (p = 0.821), tumor stage (p = 0.221), tumor location (p = 0.895), histologic grade (p = 0.173), or 3-year overall survival rate (55.6% vs. 50.0%, p = 0.784). However, the PG had a higher postoperative complication rate (44% vs. 17%, p = 0.025), longer intensive care unit stay (4.8 days vs. 0.8 days, p = 0.047), and lower 3-year recurrence-free survival (42.4% vs. 78.8%, p = 0.025) than the OG. In the multivariate analysis, perforation was significantly increased risk of recurrence (hazard ratio = 3.67, 95% confidence interval: 1.049–12.839, p = 0.042).

Conclusion

Patients with colon cancer initially presenting with perforation had poorer recurrence-free survival, higher postoperative complication rates, and longer ICU stays than those who had obstruction.

Analysis of Critical COVID-19 Cases Among Children in Korea

BACKGROUND

Coronavirus disease 2019 (COVID-19) is generally asymptomatic or mild in otherwise healthy children, however, severe cases may occur. In this study, we report the clinical characteristics of children classified as critical COVID-19 in Korea to provide further insights into risk factors and management in children.

METHODS

This study was a retrospective case series of children < 18 years of age classified as critical COVID-19. Cases were identified by the Korea Disease Control and Prevention Agency surveillance system and medical records were reviewed. Critical COVID-19 was defined as cases with severe illness requiring noninvasive (high flow nasal cannula, continuous positive airway pressure, or bilevel positive airway pressure) or invasive mechanical ventilation, extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy (CRRT), between January 20, 2020 and October 7, 2021.

RESULTS

Among 39,146 cases diagnosed with COVID-19 in subjects < 18 years of age, eight cases (0.02%) were identified as critical COVID-19. The median age was 13 years (range 10 month-17 years) and male-to-female ratio was 1:1. Three children had underlying diseases; one child has asthma and major depressive disorder, one child had Lennox-Gastaut syndrome and one child had mental retardation and was newly diagnosed with type 2 diabetes mellitus with the diagnosis of COVID-19. Among the eight children, seven were obese (body mass index range [BMI] median 29.3, range 25.9-38.2, weight-for-length > 97% for infant) and one was overweight (BMI 21.3). All patients had fever, six patients had dyspnea or cough and other accompanied symptoms included sore throat, headache, lethargy and myalgia. Radiologic findings showed pneumonia within 1-8 days after symptom onset. Pneumonia progressed in these children for 2-6 days and was improved within 5-32 days after diagnosis. Among the eight critical cases, remdesivir was administered in six cases. Steroids were provided for all cases. Inotropics were administered in one case. Six cases were treated with noninvasive mechanical ventilator and three required mechanical ventilator. One case required ECMO due to acute respiratory distress syndrome. All cases were admitted to the intensive care unit and admission period ranged from 9-39 days. Among all critical COVID-19 cases < 18 years of age, there were no fatal cases.

CONCLUSION

To develop appropriate policies for children in the COVID-19 pandemic, it is important to monitor and assess the clinical burden in this population.

Early supplemental parenteral nutrition is associated with reduced mortality in critically ill surgical patients with high nutritional risk

BACKGROUND & AIMS

Adequate nutritional provision is important for critically ill patients to improve clinical outcomes. Starting enteral nutrition (EN) as early as possible is recommended and preferred to parenteral nutrition (PN). However, patients who undergo emergency abdominal operations may have alterations in their intra-abdominal environment and gastrointestinal motility leading to limitation in starting an enteral diet. Therefore, our study was designed to evaluate the benefit of early supplemental PN to achieve adequate calorie and protein supply in critically ill patients undergoing surgery who are not eligible for early EN.

METHODS

We reviewed the medical records of 317 patients who underwent emergency abdominal surgery for complicated intra-abdominal infection (cIAI) between January 2013 and December 2018. The nutritional data of the patients were collected for 7 days in maximum, starting on the day of intensive care unit (ICU) admission. The patients were divided by low or high malnutrition risk using the modified Nutrition Risk in Critically ill (mNUTRIC) score and body mass index. The low- and high-risk groups were subdivided into the following two categories: those who received PN within 48 h ("early") and those who did not ("usual"). Data regarding the baseline characteristics, initial severity of illness, morbidity, and mortality rates were also obtained. The average calorie and protein supply per day were calculated in these groups.

RESULTS

Patients in all groups showed no significant differences in baseline characteristics, initial status, and infectious complications. In terms of outcomes, patients with low malnutrition risk had no significant difference in mortality. However, among patients with high malnutrition risk, the "Early" group had lower rates of 30-day mortality (7.6% vs. 26.7%, p = 0.006) and in-hospital mortality (13.6% vs. 28.9%, p = 0.048) than those of the "Usual" group. Kaplan-Meier survival curves for 30-day mortality in these groups also showed a statistically significant difference (p = 0.001). The caloric adequacy of the "Early" group and the "Usual" group were 0.88 ± 0.34 and 0.6 ± 0.29, respectively. Amounts of protein received were 0.94 ± 0.39 g/kg in the "Early" group and 0.47 ± 0.34 g/kg in the "Usual" group, respectively. There was no significant difference in infectious complications between both groups.

CONCLUSIONS

Mortality in patients with high malnutrition risk who received early PN supply within 48 h after emergency surgery for cIAI was lower than those who did not receive PN earlier. PN may be necessary to fulfill the caloric and protein requirements for critically ill patients who cannot achieve their nutritional requirements to the fullest with EN alone.

Association between postoperative fluid balance and mortality and morbidity in critically ill patients with complicated intra-abdominal infections: a retrospective study

Background

Postoperative fluid overload may increase the risk of developing pulmonary complications and other adverse outcomes. We evaluated the impact of excessive fluid administration on postoperative outcomes in critically ill patients.

Methods

We reviewed the medical records of 320 patients admitted to intensive care unit (ICU) after emergency abdominal surgery for complicated intra-abdominal infection (cIAI) between January 2013 and December 2018. The fluid balance data of the patients were reviewed for a maximum of 7 days. The patients were grouped based on average daily fluid balance with a cutoff value of 20 ml/kg/day. Propensity score matching was performed to reduce the underlying differences between the groups.

Results

Patients with an average daily fluid balance of ≥20 ml/kg/day were associated with higher rates of 30-day mortality (11.8% vs. 2.4%; P=0.036) than those with lower fluid balance (<20 ml/kg/day). Kaplan-Meier survival curves for 30-day mortality in these groups also showed a better survival rate in the lower fluid balance group with a statistical significance (P=0.020). The percentage of patients who developed pulmonary consolidation during ICU stay (47.1% vs. 24.7%; P=0.004) was higher in the fluid-overloaded group. Percentages of newly developed pleural effusion (61.2% vs. 57.7%; P=0.755), reintubation (18.8% vs. 10.6%; P=0.194), and infectious complications (55.3% vs. 49.4%; P=0.539) showed no significant differences between the two groups.

Conclusions

Postoperative fluid overload in patients who underwent emergency surgery for cIAI was associated with higher 30-day mortality and more frequent occurrence of pulmonary consolidation. Postoperative fluid balance should be adjusted carefully to avoid adverse clinical outcomes.

Impact of a multidisciplinary quality improvement initiative to reduce inappropriate usage of stress ulcer prophylaxis in hospitalized patients

AIMS

To promote effective methods to improve overutilization patterns of acid-suppressive therapy in hospitalized patients and to evaluate the impact of multidisciplinary team efforts to reduce inappropriate use of stress ulcer prophylaxis in low-risk patients.

METHODS

A multidisciplinary quality improvement initiative incorporating education, medication use reviews and reconciliation, and pharmaceutical intervention was implemented in June 2018 for surgical patients hospitalized via emergency department. For the pre-post analysis and time series analysis, patients admitted during April and May were classified into the pre-intervention cohort and those admitted during July and August into the post-intervention cohort.

RESULTS

Three hundred and seventeen patients were included in this study (153 and 164 in the pre- and post-intervention cohorts, respectively). The multidisciplinary program was effective in reducing overuse of stress ulcer prophylaxis and healthcare expenses associated with it. Biweekly education on risk factors warranting stress ulcer prophylaxis was provided for clinicians, and acid-suppressive therapy was removed from a preset list of admission orders. The incidence of inappropriate prophylaxis use declined substantially following intervention in overall patients (OR = 0.51, P = 0.01) and a significant decrease was primarily observed among non-ICU patients (OR = 0.50, P = 0.01). Interrupted time series analysis confirmed the significant decline in inappropriate use post intervention (coefficient = -0.63, P < 0.001). The total healthcare expenses associated with such overuse decreased by 58.5% from US$ 19.39 to US$ 8.04 per 100 patient-days.

CONCLUSIONS

Our multidisciplinary team efforts were associated with improvement in stress ulcer prophylaxis overuse patterns, resulting in a substantial decrease in the incidence of inappropriate use, especially in general wards, and associated healthcare costs.

Association of Initial Low Serum Selenium Level with Infectious Complications and 30-Day Mortality in Multiple Trauma Patients

Low serum selenium levels are commonly observed in critically injured multiple trauma patients. This study aimed to identify the association between initial serum selenium levels and in-hospital infectious complications in multiple trauma patients. We retrospectively reviewed multiple trauma patients admitted between January 2015 and November 2017. We selected 135 patients whose serum selenium levels were checked within 48 h of admission. Selenium deficiency was defined as a serum selenium level <70 ng/mL. Survival analyses of selenium deficiency and 30-day mortality were performed. Multivariate logistic regression analysis was performed to identify the association between initial serum selenium level and in-hospital infectious complications. Thirty-day mortality (8.3% vs. 0.0%; p = 0.018) and incidence rates of pneumonia (66.7% vs. 28.3%; p < 0.001) and infectious complications (83.3% vs. 46.5%; p < 0.001) were higher in patients with selenium deficiency than in patients without selenium deficiency. Kaplan–Meier survival cures also showed similar results (log rank test, p = 0.021). Of 135 patients, 76 (56.3%) experienced at least one infectious complication during admission. High injury severity score (ISS, odds ratio (OR) 1.065, 95% confidence interval (CI) 1.024–1.108; p = 0.002) and selenium deficiency (OR 3.995, 95% CI 1.430–11.156; p = 0.008) increased the risk of in-hospital infectious complications in multiple trauma patients. Patients with selenium deficiency showed higher 30-day mortality and higher risks of pneumonia and infectious complications.

Predictors of early weaning failure from mechanical ventilation in critically ill patients after emergency gastrointestinal surgery: A retrospective study

Mechanical ventilation (MV) is the most common therapeutic modality used for critically ill patients. However, prolonged MV is associated with high morbidity and mortality. Therefore, it is important to avoid both premature extubation and unnecessary prolongation of MV. Although some studies have determined the predictors of early weaning success and failure, only a few have investigated these factors in critically ill surgical patients who require postoperative MV. The aim of this study was to evaluate predictors of early weaning failure from MV in critically ill patients who had undergone emergency gastrointestinal (GI) surgery.The medical records of 3327 adult patients who underwent emergency GI surgery between January 2007 and December 2016 were reviewed retrospectively. Clinical and laboratory parameters before surgery and within 2 days postsurgery were investigated.This study included 387 adult patients who required postoperative MV. A low platelet count (adjusted odds ratio [OR]: 0.995; 95% confidence interval [CI]: 0.991-1.000; P = .03), an elevated delta neutrophil index (DNI; adjusted OR: 1.025; 95% CI: 1.005-1.046; P = .016), a delayed spontaneous breathing trial (SBT; adjusted OR: 14.152; 95% CI: 6.571-30.483; P < .001), and the presence of postoperative shock (adjusted OR: 2.436; 95% CI: 1.138-5.216; P = .022) were shown to predict early weaning failure from MV in the study population.Delayed SBT, a low platelet count, an elevated DNI, and the presence of postoperative shock are independent predictors of early weaning failure from MV in critically ill patients after emergency GI surgery.

Addition of lactic acid levels improves the accuracy of quick sequential organ failure assessment in predicting mortality in surgical patients with complicated intra-abdominal infections: a retrospective study

Background

The quick sequential organ failure assessment (qSOFA) alone has a poor sensitivity for predicting mortality in patients with complicated intra-abdominal infections, and plasma lactate levels have been shown to have a strong association with mortality in critically ill patients. Therefore, this study aimed to compare the performance of qSOFA with a score derived from a combination of qSOFA and serum lactate levels for predicting mortality in surgical patients with complicated intra-abdominal infections.

Methods

This retrospective study was performed at a university hospital. The medical records of 457 patients who presented to the emergency department (ED) between January 2008 and December 2016 and required emergency gastrointestinal surgery for a complicated intra-abdominal infection were reviewed retrospectively. qSOFA criteria, sequential organ failure assessment (SOFA) scores, and plasma lactate levels during their ED stay were collected. We performed area under receiver operating characteristic (AUROC) curve and sensitivity analysis to compare the performance of qSOFA alone with that of a score derived from the use of a combination of the qSOFA and lactate levels for predicting patient mortality.

Results

Fifty patients (10.9%) died during hospitalization. The combined qSOFA and lactate level score was superior to qSOFA alone (AUROC = 0.754 vs. 0.717, p = 0.039, respectively) and comparable to the full SOFA score (AUROC = 0.754 vs. 0.795, p = 0.127, respectively) in predicting mortality. Sensitivity and specificity of qSOFA alone were 46 and 86%, respectively, and those of the combined score were 72 and 73%, respectively (p < 0.001).

Conclusion

A score derived from the qSOFA and serum lactate levels had better predictive performance with higher sensitivity than the qSOFA alone in predicting mortality in patients with complicated intra-abdominal infections and had a comparable predictive performance to that of the full SOFA score.

Expression of bovine rotavirus VP8 and preparation of IgY antibodies against recombinant VP8

Group A rotavirus is the leading cause of acute gastroenteritis in cattle and swine. Although, vaccination against this virus is an effective strategy for prevention, additional strategy to control disease is necessary. Egg yolk immunoglobulin (IgY)-based passive immunization could be a better option in preventing this disease. Bovine rotavirus (BRV) is group A rotavirus and possesses a genome of 11 segments of double-stranded RNA. The outer layer of capsid is composed of two proteins (VP7 and VP4), which induce virus neutralizing antibodies. Trypsin cleavage of VP4 produces VP8 (28 kDa) and VP5 (60 kDa) fragments. Since a number of studies have demonstrated the induction of neutralizing antibodies using VP8 subunit vaccines, we have produced IgY against the recombinant VP8. The cDNA spanning the VP8 subunit was amplified from bovine rotavirus-infected cells and cloned into pET21d(+) expression vector to generate recombinant VP8. The resulting carboxy-terminal His-tagged VP8 proteins were expressed in Escherichia coli strain BL21(DE3) by isopropyl β-D-1-thiogalactopyranoside (IPTG) induction. The recombinant proteins were purified using Ni-NTA agarose beads, and the purified protein was used as the immunizing agent to produce polyclonal antibodies in chicken. The resulting polyclonal antisera specifically recognized VP8 in Western blot assay and were able to neutralize BRV replication in cell cultures. These results demonstrate that IgY can be used in immunological assays and, in addition, in passive immunization of newborn calves against BRV.

Use of IgY antibody to recombinant avian reovirus σC protein in the virus diagnostics

Avian reovirus (ARV) is an important agent of several diseases causing considerable losses in poultry farming. An outer capsid protein (σC) of ARV, is known as a virus-cell attachment protein essential for virus infectivity. In this study, the σC gene of ARV was cloned and expressed in Escherichia coli. The expressed recombinant protein was used as immunogen for raising a specific IgY antibody in laying hens. At 14 weeks post immunization, the antibody titers in serum and egg yolk reached 302,000 and 355,000, respectively. The IgY antibody was capable to neutralize ARV in BHK-21 cells and it strongly reacted in ELISA with ARV but not with heterologous viruses. The IgY antibody detected ARV in field samples of infected animal tissues in dot blot assay. These results suggest that an efficient, economic and rapid diagnostics of ARV can be performed routinely using the IgY antibody against a recombinant ARV σC protein.

Tetherins of various species inhibit the release of porcine endogenous retrovirus from human cells

Pigs are considered as suitable xenotransplantation organ donors. However, the risk of pathogen transmission from pigs to human is a major concern in the transplantation of porcine tissues since it had been shown that porcine endogenous retroviruses (PERVs) can infect human cells. Tetherin has recently been described as a host restriction factor that blocks the release of virus particles from cells infected with some enveloped viruses. We compared tetherins derived from various species in their activity against PERVs by using a pseudotype assay. The results showed that (i) mammalian tetherins inhibit spread of PERVs, (ii) murine and rhesus tetherins are weaker inhibitors than canine and feline ones, (iii) human tetherin is induced by interferon alpha (IFN-α) and (iv) IFN-α treatment of 293T-PERV-PK-CIRCE cells reduced PERV release. We conclude that transgenic overexpression of tetherin combined with its induction by IFN-α may reduce the risk of PERV dissemination in xenotransplantation.

Microelectrode recording: lead point in STN-DBS surgery

BACKGROUND

Microelectrode recording is an integral part of many surgical procedures for movement disorders. We evaluate the Lead point compared to the NeuroTrek system. We used NeuroTrek in 18 Parkinsonian patients, Lead point-4 in 12 patients, during STN-DBS surgery. We compared MR-Stir image with Microelectrode recording.

METHOD

The MicroGuide system with its integrated screen display provides the user with all the information needed during the surgery on its screen. Microelectrode recordings showed characteristic neuronal discharges on a long trajectory (5-6 mm), intraoperative stimulation induces dramatic improvement of Parkinsonian motor symptoms.

FINDINGS

Microrecording data of the Leadpoint showed high background activity, and firing rate of 14-50 Hz. The discharge pattern is typically chaotic, with frequent irregular bursts and pauses.

DISCUSSION

The microelectrode recording of the neuroTrek and Lead point-4 showed unique results of the typical STN spike. The DBS effect is maximized associated by MER mapping.

The mouse gap junction gene connexin29 is highly expressed in sciatic nerve and regulated during brain development

A novel mouse gap junction gene, coding for a presumptive protein of 258 amino acids (molecular mass: 28 981 Da), has been designated connexin29. This single copy gene was mapped to distal mouse chromosome 5 and shows 75% sequence identity to a human connexin30.2 sequence in the database. Connexin29 mRNA (4.4 kb) is highly expressed in mouse sciatic nerve and less abundant in spinal cord as well as in adult brain, where it increased 12-fold between day 7 and 14 post partum. Our expression data suggest that the new connexin gene is active in myelin-forming glial cells.

Functional expression of the new gap junction gene connexin47 transcribed in mouse brain and spinal cord neurons

A new mouse gap junction gene that codes for a protein of 46,551 Da has been identified and designated connexin47 (Cx47). It mapped as a single-copy gene to mouse chromosome 11. In human HeLa cells and Xenopus oocytes, expression of mouse Cx47 or a fusion protein of Cx47 and enhanced green fluorescent protein induced intercellular channels that displayed strong sensitivity to transjunctional voltage. Tracer injections in Cx47-transfected HeLa cells revealed intercellular diffusion of neurobiotin, Lucifer yellow, and 4',6-diamidino-2-phenylindole. Recordings of single channels yielded a unitary conductance of 55 pS main state and 8 pS substate. Cx47 mRNA expression was high in spinal cord and brain but was not found in retina, liver, heart, and lung. A low level of Cx47 expression was detected in ovaries. In situ hybridizations demonstrated high expression in alpha motor neurons of the spinal cord, pyramidal cells of the cortex and hippocampus, granular and molecular layers of the dentate gyrus, and Purkinje cells of the cerebellum as well as several nuclei of the brainstem. This expression pattern is distinct from, although partially overlapping with, that of the neuronally expressed connexin36 gene. Thus, electrical synapses in adult mammalian brain are likely to consist of different connexin proteins depending on the neuronal subtype.

A single amino acid change in the murine leukemia virus capsid gene responsible for the Fv1(nr) phenotype

The nr allele at the mouse Fv1 restriction locus governs resistance to B-tropic and some N-tropic murine leukemia viruses (MLVs). Sequence analysis and site-specific mutagenesis of N-tropic MLVs identified a single amino acid difference responsible for this restriction that is distinct from the site that governs N or B tropism. Viruses with other substitutions at this site were evaluated for altered replication patterns.

Molecular biological characterization of enterovirus variant isolated from patients with aseptic meningitis

In Korea, there was a big outbreak of aseptic meningitis in 1993. Six clinical isolates of enterovirus were obtained from patients with aseptic meningitis and were identified as echovirus type 9 by serotyping with a pool of neutralizing antisera. For molecular characterization of the isolates, the nucleotide sequences of 5'-noncoding region (NCR), VP4, VP2, VP1, 2A and 2C regions of the isolates were compared with the corresponding regions of echovirus type 9 Hill and Barty strains. Unlike Hill strain, Barty strain contained a C-terminal extension to the capsid protein VP1 with an RGD (argnine-glycine-aspartic acid) motif. To determine whether similar structural features were present in our isolates, their nucleotide sequences including the VP1 region were analyzed. All isolates exhibited the VP1 extension with the RGD motif. We concluded the Korean isolates in the year of 1993 as the echovirus type 9 Barty strain although the isolates showed 15-20% nucleotide sequence differences in the several genomic regions.

Rapid subgrouping of nonpolio enterovirus associated with Aseptic Meningitis by RFLP (Restriction Fragment Length Polymorphism) assay

In Korea, there was a big outbreak of Aseptic Meningitis due to enterovirus infection in 1993. Since virus isolation and neutralizing tests are too laborious and time-consuming for the detection of enterovirus from clinical specimen, we have developed a new molecular identification method for rapid subgrouping of isolates from patients with aseptic meningitis. For the rapid subgrouping of isolates, RT-PCR (Reverse Transcription-Polymerase Chain Reaction) and RFLP (Restriction Fragment Length Polymorphism) assays were used. We have selected two oligonucleotide primers from the conserved 5'-UTR/VP2 and VP1 regions. A 652 bp (base pair) product was amplified from the 5'-UTR/VP2 region of reference viruses and the isolates. For the subgrouping of the isolates by RFLP assay, we have used 12 reference viruses (Echovirus, E6, E9, E11, E12, Coxsackievirus, CB1, CB3, CB4, CB5, Coxsackievirus, CA9, CA16, CA21, CA24), which are the common viral agents associated with aseptic meningitis. By using subgroup-specific restriction enzymes BsmAI, , HinP1I, and PleI, the isolates were classified into Echovirus subgroups. We have also shown that subgrouping of the isolates by RFLP assay based on the VP1 region is possible.

GB virus C/hepatitis G virus infection among Korean patients with liver diseases and general population

GB virus C and hepatitis G virus (GBV-C/HGV) have been identified from the patients with acute or chronic liver diseases as possible agents of non-B, non-C hepatitis by two different groups, independently. To investigate whether GBV-C/HGV plays a role among Korean patients with liver diseases, GBV-C/HGV RNA were evaluated in 337 sera by the reverse transcription polymerase chain reaction (RT-PCR) using specific primers derived from 5'-noncoding region of GBV-C/HGV genome. GBV-C/HGV RNA was identified in 11/337 (3.3%). They consisted of 1/160 (0.6%) and 10/177 (3.3%) among the general population and patients with liver diseases, respectively (P < 0.01). Nucleotide sequences of all PCR amplicons were determined by the dideoxy chain termination method and analyzed by molecular evolutionary methods. The phylogenetic tree showed all sequences could be divided into three genotypes. These results indicate that: (1) GBV-C/HGV already exist in Korea; (2) GBV-C/HGV may play some role as an etiologic factor among the Korean patients with liver diseases; (3) GBV-C/HGV infection is rare among Korean general population; and (4) there are at least three different types of GBV-C/HGV in Korea.

Nucleotide sequencing of a part of the 5'-noncoding region of echovirus type 9 and rapid virus detection during the acute phase of aseptic meningitis

A part of the 5'-noncoding region of echovirus type 9 isolates was sequenced, and an attempt was made for rapid virus detection in clinical samples obtained from 22 subjects hospitalized with aseptic meningitis. The sequence identity of 440-bp products amplified from the region by RT-PCR was 87.7% between the standard echovirus type 9(Hill strain) and the isolates. Specific IgM antibodies to Hill strain were positive in 45.5% by immunofluorescent antibody staining of virus-infected cells. A high detection rate of PCR products was observed in cerebrospinal fluids (CSFs; 54.5%) at admission, and in peripheral mononuclear cells (PMCs; 72.7%) at the end of hospitalization. Viral genomes were detectable for 2 days in serum samples, and for 6 days in PMC samples after onset of disease. When specific IgM antibody titers were less than 1:40, the amplification rate of viral genome from serum samples was 50.0%. These results indicate that the combination of specific IgM determination and viral genome amplification from CSFs will be a rapid and reliable method for early diagnosis.

Microsatellite instability-associated mutations associate preferentially with the intestinal type of primary gastric carcinomas in a high-risk population

Most colon cancers exhibiting microsatellite instability (MI), a mutator phenotype of mismatch repair failure, are associated with mutations of the transforming growth factor-beta receptor type II genes (TGF-beta RII). Of intestinal- and diffuse-type gastric carcinomas, the former have been thought to arise from intestinal metaplasia in which gastric mucosa resembles intestinal mucosa. To evaluate the preferential histological type of MI-associated mutations in the development of gastric carcinoma, mutations of TGF-beta RII, p53, and p16 were analyzed for the two types of primary gastric carcinomas showing MI. Of 50 primary gastric carcinomas, including 33 intestinal types and 17 diffuse types, 15 cases (30%) demonstrated MI at 1 or more of the 11 microsatellite markers tested. The 15 MI cases were classified into two groups, widespread MI and low-level MI, based on the number of markers exhibiting the instability. Eleven were widespread MIs, and the remaining four cases were low-level MIs. Ten of the 11 (91%) widespread MIs were of the intestinal type, and 1 case (9%) was of the diffuse type. Of the 11 widespread MIs, 10 cases (91%) demonstrated frameshift mutations within the polyadenylate tract of the TGF-beta RII. The frameshift mutation was rarely detected at p53 and p16 (1 of 11, 9%). In contrast, the four low-level MI cases had no frameshift mutations within the repeat sequences of TGF-beta RII, p53, and p16, but two of the four cases demonstrated base substitution mutations within p53. Our results suggest that mismatch repair failure can mutate the TGF-beta RII and may provide one of the pathways for the development of the intestinal-type gastric carcinoma in high-risk populations.

Genomic characterization of M and S RNA segments of hantaviruses isolated from bats

Genomic analysis of three Hantaan-like virus isolates from bats was performed. Cleavage patterns of reverse transcription (RT)-polymerase chain reaction (PCR) products and nucleotide sequences of G2 region of M RNA segment and N protein region of S RNA segment of the isolates were compared to that of Hantaan 76-118 strain. Genomic characteristics of the bat isolates were identical to that of Hantaan virus.